1. Field of the Invention
The present invention relates to a battery backup device, and more particularly, to a battery backup device having data link and storage functions.
2. Description of the Related Art
A portable digital device or a mobile device can now exchange various contents with a computer through data communication. In this case, the portable digital device or the mobile device is connected to the computer by a connector such as a universal serial bus (USB) connector. However, since a battery of the portable digital device or the mobile device is used up in a short period of time, a battery backup device is being developed to charge the battery whenever necessary.